How much do you trail brake when tracking?
#16
When I TB I usually use it right up until I turn-in, releasing on turn-in,
or in a real tight corner, actually turn with the brake still applied and release for the sharp rotation.
Not trying to argue. I am sure you are a great driver. I am just saying what I have learned from pro's.
#17
Just to add, the point here is to get the weight of the car to transfer to the front tyre contact patches thus increasing grip and aiding turn in.
Try lifting off the brakes gently as you pick up the throttle to balance the car. By the apex you should be flat. You should stay flat from there on.
In doing so you'll carry more speed because you're using the rear weight biased layout of the 911 to your advantage.
Learning, practicing and getting it right is one reason why 911's are so rewarding to drive.
Try lifting off the brakes gently as you pick up the throttle to balance the car. By the apex you should be flat. You should stay flat from there on.
In doing so you'll carry more speed because you're using the rear weight biased layout of the 911 to your advantage.
Learning, practicing and getting it right is one reason why 911's are so rewarding to drive.
#18
Smooth inputs all the time -- braking or throttle. No time on the track where you are static (coasting). So, full throttle until you brake and continue braking (trail) into the turn until you ease out of brakes and ease into throttle until you are flat at the apex. Of course it depends on the turn, but you get my drift. So many threshold brake in a straight line and find their comfortable speed for the turn and then ease on some throttle. In that situation, you probably could have waited to brake another 50 or 100 feet. Consider the point where you can power back on and work backwards from there using trail braking last and threshold first. Note: Your results may vary...
#19
MURRY
Murry, not Murray, folks. He is one of our track driving "mentors"...my wife (like Bob R's) also tracks. First time we had David drive one of our cars I could not believe how much trail braking he did. He told me during one of our first lessons that the only time he had his foot only on the throttle was on the straights! David M sits in the car instructing on the communicator, very light hold of the wheel, car at the adhesion limit, doing times us "non pro drivers" just can't do. If you want to learn the "science" of trail braking, or for that matter, how to really reduce your lap times in any car, there's no one better coach to hire than David M.
#20
I did a DE at Road America last month with an instructor who has drives a GT3 (quite quickly) about 40 track days each year. He was trying to get me to trail the brake into every corner almost to the apex where he had me getting quickly, but smoothly onto the throttle. I only did it well about 3 times in 200 turns, but when I did, it felt great (and fast) and my lap times were actually a little better on the laps where I came close to getting right a couple of times.
#21
David Murry is an AMAZING driver!!!
For those of you who have had the pleasure of having him ride/coach you are lucky.
Trail braking is a very useful tool keeping keeping a bit of weight on the front end to aid turn-in and can be as little as having the brake lights illuminated.
For those of you who have had the pleasure of having him ride/coach you are lucky.
Trail braking is a very useful tool keeping keeping a bit of weight on the front end to aid turn-in and can be as little as having the brake lights illuminated.
#22
In any form of pro racing trail braking is done into every corner. Why do you think F1 cars sometimes smoke up their inside front wheels on corner entry? That's right, they are trail braking massively into the corners all the way to the apex. Sometimes they brake too much therefore get some lockup.
If you want to go as fast as the car can possibly go on the track you have to do that. But consider the fact that it is your car and most likely you don't have a spare waiting for you in the paddock. The faster you go the more likely you need a spare car in the paddock.
I only trail brake into slower corners. At that point if I get it wrong most likely it will be embarrassing but I may not need to look for a spare car.
If you want to go as fast as the car can possibly go on the track you have to do that. But consider the fact that it is your car and most likely you don't have a spare waiting for you in the paddock. The faster you go the more likely you need a spare car in the paddock.
I only trail brake into slower corners. At that point if I get it wrong most likely it will be embarrassing but I may not need to look for a spare car.
#24
I agree with NoSubEDU, the 993s are easier to trailbrake with. the 997 with their traction control and god knows what else is less of a momemtum car. you just get in and get out. the speeds are higher to begin with and the car is much heavier (compared to a 993). Bob Rouleau's description is the right way to drive this car for fast. How much you trail into the corner can change depending on the speed you are carrying. Personally, I'd rather get on the gas early than get off the brake late. the other thing to remember is that the DE line is usually later than the racing line. so if you are racing , like Dave M, you are trying to protect your corner, you have no choice but to trail brake.
#25
I've only had a Porsche since March and only have about 3500 miles on the track in my 997S at Lime Rock and Watkins Glen (black run group), so I'm far from an expert on the particular dynamics of a high-power / high-weight Porsche or on differences between the models. But I'd have to think vehicle dynamics and physics are pretty similar regardless of what hardware you bring to the track. As for PSM and other high-tech items interfering -- they absolutely do not if you are as smooth as you should be. As with any car, there's a balance point where you leave the brakes for the power. That fulcrum is what we're talking about finding via whatever braking style you are comfortable with. You could threshold brake in a straight line, then "coast" or use maintenance throttle to the apex and then pour it on, or you can extend the straight and trail brake / turn right up to the apex and then pour it on. Maximum adhesion is still maximum adhesion -- the speed at which your car will stay on the track... Granted, I'm still learning the nuances of a rear-engined car, but the results so far with a stock car has been encouraging -- 1:02 at LRP and 2:15 at WGI with plenty of room to improve. A big part of shaving time off has been later braking, threshold to trail (ie: T1, Bus Stop in particular). It has taken some getting used to because my E46 M3 was not going 150 into the Bus Stop -- at that speed, believing the brakes are going to be enough to trail into the Bus Stop has taken some faith
#26
Maximum adhesion is still maximum adhesion -- the speed at which your car will stay on the track... A big part of shaving time off has been later braking, threshold to trail (ie: T1, Bus Stop in particular). It has taken some getting used to because my E46 M3 was not going 150 into the Bus Stop -- at that speed, believing the brakes are going to be enough to trail into the Bus Stop has taken some faith
Maximum adhesion is greater if you are not braking. Braking takes up part of your allocated grip and so there is less available for turning
Late braking shaves only a little time. Early on the throttle and driving the proper line will be much more effective in lowering times. Proper trail-braking helps with these two points also.
One more thing; trail-braking is NOT late braking. One may trail-Brake while braking late or early. Braking slows the car, trail-braking controls the car. The two ALMS drivers I've ridden with trail-brake just about everywhere. and, they don't late-brake at all unless they are setting up a pass in the turn. In fact, they tended to start braking earlier than I would have. They are on the throttle sooner too.
Last edited by allegretto; 11-05-2007 at 10:07 AM.